MELBOURNE, Australia — This was one occasion where Novak Djokovic couldn't really empathize with Andy Murray, his long-time friend.

As he prepared to receive the trophy for the Australian Open winner for a fifth time in five trips to the final at Melbourne Park, Djokovic turned to Murray late Sunday and offered his congratulations on his friend's recent engagement.

Nice segue. Murray — to set the record straight — had just lost an Australian Open final for the fourth time, including three at the hands of Djokovic. Murray won the U.S. Open in 2012 and Wimbledon in 2013 to end decades-long droughts at the majors for British men, but was clearly upset at his inability to crack it in Melbourne after this 7-6 (5), 6-7 (4), 6-3, 6-0 defeat.

"I wish you a wonderful wedding and many kids," Djokovic said, kicking off his trophy acceptance speech. Murray smiled. His fiancee, Kim Sears, applauded from her seat in the crowd. She'd already drawn attention for her shirt that was emblazoned with the words "Parental Advisory Explicit Content" — a humorous reaction to being caught on camera apparently using expletives during Murray's semifinal.

"It's slightly different thinking for me now since I became a father and a husband," Djokovic explained. "I apologize for changing the subject."

His outlook on life had changed between his two most recent trips to Australia. He married long-time partner, Jelena, and the couple had a son, Stefan, in late October.

He said his first Grand Slam title since his marriage and the birth of his son had a "deeper meaning, more intrinsic value."

"Getting married and becoming a father was definitely something that gave me a new energy, something that I never felt before," he said. "And right now everything has been going in such a positive direction in my life. I'm so grateful for that. So I try to live these moments with all my heart."

Djokovic now has eight major titles, including his five in Australia, where he won his first Grand Slam title in 2008 and then won three straight from 2011 before losing in the quarterfinals last year to Stan Wawrinka.

The 27-year-old Serbian is now second on the list of all-time Australian Open winners — behind only Roy Emerson, who won six titles in the 1960s and who was in the crowd Sunday.

After two tough first sets decided in tiebreakers, when there was eight breaks of serve and plenty of tension, Djokovic broke open the match after the sixth game of the third set and won 12 of the last 13 games. In the first set, he tumbled to the court, lunging to reach a volley, and needed treatment on his right thumb — shaking his right hand repeatedly. The second set was disrupted for five minutes by a political protester running onto the court, causing a lockdown of sorts, and another momentum shift. In the third set, it was fatigue, with Djokovic appearing to be struggling badly.

"I was just weak. I went through the physical crisis in the matter of 20 minutes and, honestly, didn't feel that too many times in my career," Djokovic said. "But knowing in the back of my mind that it was a similar situation two years ago in Australian Open final, where two sets went over two hours, was a similar battle. Then I felt that I had some physical edge over him in that match. That was in back of my mind. That was something that kept me going."

After the match, Djokovic had plenty left in his legs, able to high-five a long line of ballboys after the presentation.

"Novak has won five times here now, there's no disgrace in losing to him," said Murray, who now trails 16-8 in career head-to-head matches.

Murray and Djokovic have known each other since their early junior days, and often hit against each other for practice. Seeing Djokovic in pain apparently unnerved Murray.

"The third set was frustrating because I got a bit distracted when he, like, fell on the ground after a couple of shots," Murray said. "It appeared that he was cramping, and then I let that distract me a little bit. That's what I'm most disappointed about, not so much the fourth set because I think, especially at the end of it, he was just going for everything, and it was going in. But the third set was more frustrating for me.

"Obviously had opportunities in the first three sets. Then the fourth set ... he was just ripping everything. Once he got up a break, he just loosened up and was just going for his shots. I couldn't recover."

Djokovic's win on Sunday followed up on top-ranked Serena Williams' win in the women's final Saturday night against Maria Sharapova, giving the 33-year-old American a sixth Australian and 19th Grand Slam title.